<nav class="navbar navbar-expand-lg navbar-light bg-light">
    <a class="navbar-brand" href="/"><span class="text-primary">bootstrap管理系统</span></a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
    </button>

    <div class="collapse navbar-collapse" id="navbarSupportedContent">
        <ul class="navbar-nav mr-auto">
            <li class="nav-item dropdown">
                <a class="nav-link dropdown-toggle" href="#" id="usersSystem" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    用户管理
                </a>
                <div class="dropdown-menu" aria-labelledby="usersSystem">
                    <a class="dropdown-item" href="/user/index">用户列表</a>
                    <a class="dropdown-item" href="#">团队列表</a>
                    <a class="dropdown-item" href="#">收益列表</a>
                </div>
            </li>
            <li class="nav-item dropdown">
                <a class="nav-link dropdown-toggle" href="#" id="tasksSystem" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    任务管理
                </a>
                <div class="dropdown-menu" aria-labelledby="tasksSystem">
                    <a class="dropdown-item" href="#">任务列表</a>
                    <a class="dropdown-item" href="#">任务审核</a>
                    <a class="dropdown-item" href="#">暂无</a>
                </div>
            </li>
        </ul>
        <form class="form-inline my-2 my-lg-0">
            <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
            <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
        </form>
    </div>
</nav>